In the related art, a parking assistance device that controls a vehicle to park in a parking area is known. The parking assistance device calculates a moving route to the parking area and steers the vehicle according to the moving route, and guides the vehicle to the parking area.
In recent years, an autonomous parking assistance control in which a brake control and an acceleration/deceleration control are performed in addition to a steering control when the parking assistance device guides the vehicle to the parking area. JP 2015-81022 is an example of the related art.
In the acceleration/deceleration control for guiding the vehicle to the parking area in the autonomous parking assistance in the related art, values of the acceleration and the deceleration are often set in advance. If the values of the acceleration and the deceleration are set in advance, it is difficult to precisely adjust the speed. Therefore, it is difficult to stop the vehicle in the parking area with high accuracy. For example, in the autonomous parking assistance, even if the acceleration/deceleration can be switched at every predetermined control cycle, in the acceleration/deceleration control using the acceleration and deceleration values set in advance, since a difference between a stop position according to the acceleration and the deceleration and a target parking position cannot be adjusted, it is difficult to stop the vehicle in the parking area with high accuracy.
Thus, a need exists for a parking assistance device and a program which is not susceptible to the drawback mentioned above.